Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <a0a70b517bf1da920dca6082afa3fbc6aba77a67.camel@intel.com>
Subject: Re: [PATCH v5 6/9] mm/demotion: Add support for removing node from
 demotion memory tiers
From:   Ying Huang <ying.huang@intel.com>
To:     "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
        linux-mm@kvack.org, akpm@linux-foundation.org
Cc:     Wei Xu <weixugc@google.com>, Greg Thelen <gthelen@google.com>,
        Yang Shi <shy828301@gmail.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Tim C Chen <tim.c.chen@intel.com>,
        Brice Goglin <brice.goglin@gmail.com>,
        Michal Hocko <mhocko@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Hesham Almatary <hesham.almatary@huawei.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Alistair Popple <apopple@nvidia.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Feng Tang <feng.tang@intel.com>,
        Jagdish Gediya <jvgediya@linux.ibm.com>,
        Baolin Wang <baolin.wang@linux.alibaba.com>,
        David Rientjes <rientjes@google.com>
Date:   Wed, 08 Jun 2022 14:59:26 +0800
In-Reply-To: <20220603134237.131362-7-aneesh.kumar@linux.ibm.com>
References: <20220603134237.131362-1-aneesh.kumar@linux.ibm.com>
         <20220603134237.131362-7-aneesh.kumar@linux.ibm.com>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.38.3-1 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Fri, 2022-06-03 at 19:12 +0530, Aneesh Kumar K.V wrote:
> This patch adds the special string "none" as a supported memtier value
> that we can use to remove a specific node from being using as demotion target.
> 
> For ex:
> :/sys/devices/system/node/node1# cat memtier
> 1
> :/sys/devices/system/node/node1# cat ../../memtier/memtier1/nodelist
> 1-3
> :/sys/devices/system/node/node1# echo none > memtier
> :/sys/devices/system/node/node1#
> :/sys/devices/system/node/node1# cat memtier
> :/sys/devices/system/node/node1# cat ../../memtier/memtier1/nodelist
> 2-3
> :/sys/devices/system/node/node1#

Do you have a practical use case for this?  What kind of memory node
needs to be removed from memory tiers demotion/promotion?

Best Regards,
Huang, YIng


[snip]